ul {
  list-style: none;
}

.main_left {
  width: 200px;
  overflow: hidden;
  /* 通过 calc 计算容器的高度 */
  height: calc(100vh - 50px);
  ul {
    display: flex;
    align-items: center;
    flex-direction: column;
    li {
      height: 70px;
      line-height: 68px;
      cursor: pointer;
      width: 200px;
      text-align: center;
      background-color: rgb(37, 52, 69);
      color: #bfcbd9;
    }
    .active li {
      color: rgb(64, 158, 255) !important;
    }
    li:hover {
      background-color: #1f2d3d;
    }
  }
}
